The present invention relates to an electrical system for monitoring the status of a number of load devices or conditions associated with the vehicle; the vehicle preferably being a truck. More particularly, this invention pertains to a vehicle condition monitoring system including means for detecting such conditions as a lamp outage and/or a "jacknife" condition. The monitoring system of this invention is most advantageous in that the detection circuitry makes use of the existing vehicle wiring.
Due to the ever increasing demand for the transportation of goods and materials, there is an ever expanding requirement for a larger number of vehicles as well as vehicles of increased size. This is evident by the greater use of trailer trucks and the tandem operation of these trucks. These trucks are not provided with sufficient safety devices for the protection of the truck-driver and others. There are not sufficient monitoring devices. Accordingly, one object of the present invention is to provide a vehicle condition monitoring system including a display panel accessible to the driver for registering a number of different fault conditions that may occur in the vehicle such as the outage of a lamp or the overheating of a brakedrum.
Another object of the present invention is to provide a monitoring system for use preferably in a trailer truck and that includes means including display means for detecting a jacknife condition of the vehicle.
Regarding the aspect of the present invention pertaining to the monitoring of the condition of certain lamps or lights in the vehicle, it is noted that the prior art shows different systems for indicating the condition of lamps in a vehicle.
The problem with the prior art systems is that they all require a separate sensing system such as a magnetic sensing system and thus the systems become quite complex especially if there are a number of lamps to monitor.
Accordingly, another object of the present invention is to provide a vehicle condition monitoring system especially for monitoring the outage of lamps wherein the continuity of the lamp is checked by impressing and sensing an alternating signal on the existing vehicle wiring.
A further object of the present invention is to provide a system in accordance with the preceding object and that is relatively inexpensive to construct, easy to install in existing vehicles and that is relatively inexpensive.
It has also been found that many times a fault condition occurs and is only temporarily corrected by the driver. For example, there may be a small leak in the vehicle radiator that activates an indicator light. The driver then fills the radiator but the problem, which is not reported, remains.
Accordingly, another object of the present invention is to provide a condition monitoring system including memory means that registers a fault condition and maintains the fault reading even if the fault is temporarily corrected.
Still another object of this invention is to provide a system as in the preceding object and where a diagnostic unit is thereafter employed to read the condition of the memory means.